Slide rule indicator



April 26, 1932. A. LANGSNER SLIDE RULE INDICATOR Filed Oct. 12, 192

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Patented Apr. 26, 1932 UNITED STATES PATENT OFFICE ADOLPI-I LANGSNER, OFCHICAGO, ILLINOIS, ASSIGNOR TO EUGENE DIETZGEN CO., OF CHICAGO,ILLINOIS, A CORPORATION OF DELAWARE SLIDE RULE INDICATOR Application ledOctober 12, 1929. Serial No. 399,321. y

This invention relates to hair line indicators of the reciprocatingslide variety, such as are generally provided on calculating slide rulesto facilitate use and enhance the ac- {B curacy of readings. It alsorelates especially improve the construction of and the method ofassembling slide rule indicators; to improve the form and arrangement ofstructural details for the rigidly joined edges of the glass indicatorplate and its lateral guide flanges; to provide for ready assemblage andrenewal of indicator parts; to provide for positive setting of an edgeflange member in its due relation to the corresponding plate edge; toprovide for resilient clamping of the plate edgesby its lateral guides;to provide for positive interlocking engagement of the guide flangeswith the corresponding edges of the plate; to provide for minimizing thelateral overhang and facial projection of the guide flange members andfastenings; to provide an indicator of this sort such that it may beassembled by purely mechanical operations and independently of heat orthe use of cement; and to assure ready convenience in reading.

An illustrative embodiment of this invention is shown in theaccompanying drawings, in which: n

Figure 1 is a fragmentary plan of a medial part ofa slide rule equippedwith an indicator embodying this invention.

Fig. 2 is a cross section onthe line 2 2 of Fig. 1.

Fig. 3 is a plan of the right hand part of the glass indicator plateshown in Fig. 1.

Fig. 4 is a plan of the indicator included in Fig. 1, except that one ofthe guide members is omitted.

Fig. 5 is a view similar to Fig. 4 but representing a modified form ofguide member.

Fig. 6 is a cross section on the line 6-6 of Fig@ 5.

Fig. 7 is similar to Fig. 6 but shows a modified form of clamp for theguide member.

Fig. 8 isalso similar to Fig. 6 but shows a further modification of theguide clamp and the plate is reversed to bring the grooves on the backside.

Fig. 9 is similar to Fig. 7 except that the guide has an inwardly turnededge instead of a set screw.

In the constructionv shown in the drawings the slide rule comprises theusual body member or ruler 1, slide 2 and the` novel form of indicator 3embodying the present invention. In each of the forms shown theindicator comprises mainly a hair line plate 4, a pair of mainly similarguides 5 and 6 secured to the lateral edges thereof for engaging thelongitudinal guideway portions of the ruler 1, as will be apparent fromFig. 2, and a spring 7 to compensate for side clearance.

Referring first to the form of plate and guides shown in Figs. 1, 2 and3, the plate 4 has cent-ral edge notches 8 and edge-parallel grooves 9on its front face to accommodate attachment of the clamping p-arts ofthe guides 5 and 6.

The said guides are alike except that guide 6 has the spring 7 attachedthereto, as shown in Fig. 2. Each guide comprises mainly a channel part10 to receive an edge of plate 4 and a flange part 11 to embraceaguideway flange 12 on the ruler 1. YThe part 11 is L-shaped with onearm 13 continuous with channel 10 and the other arm 14 underlying theruler flange 12. The leaf spring 7 is carried by the vertical arm 13 andbears against the edge of the ruler flange 12. The channel part 10 issubstantially U-shaped, with its arms or walls 15 and 16 disposedhorizontally to embrace the edges of plate 4, the lower flange 14 beingcontinuous with arm 13 of part 11. Positive clamping is enhanced andassured by means of one or more screws 17, to accommodatewhich theouter' arm is perforated at 18 and the inner arm is threaded at 19. Theinner edge of the outer arm 16 is turned downward or inclined somewhatat 2O so as to enter and engage the corresponding plate groove 9. Theplate notches 8 register with the guide holes 18 and accommodateedgewise assemblage of the plates and guides with thescrews 17 in place,but loosened. The guides may be applied endwise, provided the screws arenot in place,

as may be preferable in case the guide material is so stiff as topreclude ready edgewise assemblage. The channel wall 16 is cut at 21into 3 sections, so as to let the several parts of the clamp grip theplate 4 independently, the screw 17 being in the middle section 22.

Referring-now to Fig. 4, theplate 24 is similar to plate 4 except, thatinstead of a central notch on each supporting edge, it has a pair ofspaced notches 25 and guide 26 correspondingly has a pair of screws 17carried by its out-er sections 27 and 28.

As for Figs. 5 and 6 the plate here shown is like that of Fig. 4; butthe channel part of the guide 31 differs from the foregoing, in that theouter wall 32 of channel 33 laps past the plate groove 34 and isentirely flat except that the middle section 35 of said outer wall isindented adjacent to its edge to register with said groove, asillust-rated at 36.

Figs. 7'., 8 and 9 show merely details of variant forms for the coactingedge parts of the-plates and* guides. In each of these views the plate41 has merely an edge-parallel v groove 42 to receive a correspondinginterfitting part or fastening on the guide. In Fig. Z theI guide 43 hasa clamping channel part 44 with plain flat sides 45 and 46, except that.the front wall 46 is perforated and I threaded at 47, opposite groove42, to receive the set-screw 48'. In Fig. 8 the guide 51 is similar to,guide 43 except that instead of the frontface 52 having a set-screw theback face 53sis indented at 54, and so inwardly humped, opposite thegroove-42, the plate here being reversed; so as to cause the grooves toface backwardljf'. The indentation and hump feature at 54 may compriseone or a series of inward; deformations as might be preformed with.-acenter-punch, or it may comprise a rib parallel' with. the edge. InFig. 9 the guide 56* instead of having a screw or wall depression:merely has its outer wall 57 turned inward at its edge, as at 58 toengage the groove-42.

Certain features are common to the several forms shown. For instanceeach plate is indented or edge-grooved to assure positive setting; andeach guide clamp channel is or may. to advantage-be resilient toinherently set or spring. upon the edge of the plate. Each channel hasone of its face bearing walls' provided' with inwardly projectingmeansto positively engage a plate indentation vor groove. TheseV lockingmeans are either set permanently in the channel wall material, as at 20,36 and 54, or they may be adjustably protrusile, as at 48, where asetscrewprovides for variable degrees of clamping.. In each embodimentthe clamping action of the guide channel holds the parts rigidlyagainst. relative'vibration and the groove andshoulder featurepreventsaccidental detachment.4

Although certain specific embodiments of this invention and their modeof use have been selected to illustrate my improvements herein setforth, it is to be understood that some of the details may be altered oromitted without departing from the spirit of this invention as definedby the following claims.

I claim:

l. A slide rule indicator comprising a transparent plate having a hairline thereon to extend across the rule andy having face grooves adjacentopposite edges and extending lengthwise of the rule and lateral guidesat said edges secured in said grooves.

2. A slide rule indicator' comprising a transparent plate having a hairline thereon to extend across the rule and having face grooves adjacentopposite edges and extend.- ing lengthwise of the rule, and lateralyguides at said edges, and provided with securing means seated in saidgrooves.

3. A slide rule indicator comprising a transparent plate having a hairline thereon to extend across the rule and having face grooves adjacentopposite edges and extending lengthwise of the rule, and lateral guidesat said edges, and provided with inwardly facing marginal portionsseated in said grooves.

4. A slide rule indicator comprising a transparent plate having a hairline thereon to extend across the rule and having grooves adjacentopposite edges andl extending lengthwise of the rule, and lateral guidesat said edges, and clamps on said guides having jaws seated in saidgrooves.

5. A slide rule indicator comprising a transparent plate having a hairline-thereon to extend across the rule andhaving grooves adjacentopposite edges and extending lengthwise of the rule, and lateral guidesat said edges, clamps on said guides having jaws seatedin said grooves,and means for forcing said jaws into gripping engagement with the plate.

6. A slide rule indicator comprising a hair-lined glass plate and a pairof lateral guides attached thereto for engaging appropriate guideways onthe slide rule, each guide having a channel shaped edge part toresiliently embrace'a corresponding edge part of said plate, one side ofthe channel. being more or less inwardly protru.dent and said platebeing grooved to receive said channel.

7 A slide rule indicator comprising a rigid transparent plate and a pairof lateral guides attached thereto for engaging appropriate guideways onthe slide rule, each guide having a channel shaped edge part to embracea corresponding edge Dart ofsaid plate, one side of the channel being.more or less inwardly protrusile, and said plate being indentedaccordingly to receive the protrusile part for positive attachment ofthe guide.

8. A slide rule indicator comprising a transparent plate having a hairline thereon to extend across the rule and having a groove in one faceadjacent an edge of the plate and extending at right angles to said hairline, a guide rigidly secured to said edge of the plate, and a clampingjaw mounted on said guide and overlying said plate, said clamp j avvhaving its inner edge turned dovvn and seated in said groove.

9. A slide rule indicator comprising a transparent plate having a hairline thereon to extend across the rule, and having a marginal facegroove extending at right angles to said hair line.

10. A glass plate in combination With a clamp secured rigidly to an edgethereof, said plate being indented for positive engagement, and saidclamp Ibeing adjustably protrusive in registry With the plateindentation to effect such engagement.

1l. In combination, a glass plate and a support rigidly secured to anedge part thereof, said edge part and support being formed for positivemutual interlocking engagement, the plate being appropriately recessedtherefor and said support having an adjustable clamping part to engagethe plate recess.

12. A device of the class described comprising, in combination, ahairlined glass plate adapted to serve as a slide rule indicator7 andguides rigidly secured in mutually parallel relation to opposite edgeparts of said plate perpendicular to the hair line thereof, said edgeparts having mutually parallel grooves and said guides having adjustableclamping parts to positively engage said grooves respectively.

Signed at Chicago this 7 th day of October,

ADOLPH LANGSNEB.

